Psi-link spire

Psi-link spires are protoss long-range communication structures used for communication across interstellar distances.[1] Their range is greater than that of the Khala.

The protoss colonists on the ice moon of Kaldir tried to use three of these spires to contact the Golden Armada and inform them of the arrival of Kerrigan's swarm, but the zerg were able to destroy the structures before a signal could be sent out.[2]